System Configurations and Operating Performance of a Dynamic Voltage Restorer

Recently, attention has been paid to a voltage-sag compensator or the so-called dynamic voltage restorer (DVR), the power circuit of which consists of series and shunt converters. However, few discussions have been made on which is more practical for the DVR, a circuit configuration installing the shunt converter on the load side or that installing it on the supply side. This paper focuses on the circuit configuration installing the shunt converter on the load side, along with comparisons between the two configurations. As a result, the conventional configuration installing the shunt converter on the supply side requires a large-capacity energy storage device such as a dc link capacitor bank. On the other hand, the configuration characterized by installing it on the load side does not require any energy storage device in principle. Its operating characteristics and theoretical discussions are confirmed by computer simulation using the software package PSCAD/EMTDC.